Port Site Characterization Sampling and Analysis Plan ... · to monitor lead, zinc, and...

Port Site Characterization Sampling and Analysis Plan DeLong Mountain Regional Transportation System, Alaska Prepared for Teck Cominco Alaska Inc. Anchorage, Alaska

Port Site Characterization Sampling and Analysis Plan DeLong Mountain Regional Transportation System, Alaska Prepared for Teck Cominco Alaska Inc. Red Dog Operations 3105 Lakeshore Drive Building A, Suite 101 Anchorage, AK 99517 Prepared by Exponent 15375 SE 30th Place, Suite 250 Bellevue, WA 98007 July 2002

Doc. no. 8601997.001 1200 0702 SS07

July 25, 2002

Contents

Page

List of Figures iii

List of Tables iv

Acronyms and Abbreviations v

Port Site Characterization Sampling and Analysis Plan 1

Introduction 1

Summary of Existing Port Site Data 3 Soil Data 3 Water Data 3 Sediment Data 3

Port Site Sampling Program 4 Soil Sampling 4 Water Sampling 10 Sediment Sampling 12

Equipment Decontamination 13

Sample Identification System 13

Field Data Reporting 15

Analytical Methods 16

Disposal of Investigation-Derived Waste 16

Field Sampling Schedule 16

References 16 Appendix A EPA Method 6200 Appendix B Portable XRF Operator Qualifications and Training Appendix C Standard Operating Procedures

\\bellevue1\docs\1900\8601997.001 1200\sap.doc 8601997.001 1200 0702 SS07 ii

July 25, 2002

List of Figures

Figure 1. Location map

Figure 2. Contour map of lead concentrations in 1996

Figure 3. Contour map of zinc concentrations in 1996

Figure 4. Historical lagoon and marine sediment sample locations

Figure 5. Proposed port site characterization sampling plan

Figure 6. Detail view of proposed dock storage pad and vicinity sample locations

Figure 7. Detail view of proposed racetrack storage pad and vicinity sample locations

Figure 8. Schematic diagrams of soil sampling stations along transects

Figures are presented at the end of the main text.

\\bellevue1\docs\1900\8601997.001 1200\sap.doc 8601997.001 1200 0702 SS07 iii

July 25, 2002

List of Tables

Table 1. Mean, median, and maximum concentrations of lead and zinc in soil at port facility areas

Table 2. Mean, median, and maximum concentrations of lead and zinc in water at lagoon and marine stations

Table 3. Mean, median, and maximum concentrations of lead and zinc in sediment at lagoon and marine stations

Table 4. Proposed stations and locations for XRF analyses and soil collection samples

Table 5. Stations and locations previously identified by RWJ (1997)

Tables are presented at the end of the main text.

\\bellevue1\docs\1900\8601997.001 1200\sap.doc 8601997.001 1200 0702 SS07 iv

July 25, 2002

Acronyms and Abbreviations

CSB concentrate storage building DMTS DeLong Mountain Regional Transportation System EPA U.S. Environmental Protection Agency GPS global positioning system IDW investigation-derived waste PAC personnel accommodation complex PSMP port site monitoring program QAPP quality assurance project plan SAP sampling and analysis plan SOP standard operating procedure Teck Cominco Teck Cominco Alaska Inc. TUB truck unloading building XRF x-ray fluorescence

\\bellevue1\docs\1900\8601997.001 1200\sap.doc 8601997.001 1200 0702 SS07 v

July 25, 2002

Port Site Characterization Sampling and Analysis Plan

Introduction The Red Dog Mine is located approximately 50 miles east of the Chukchi Sea, in the western end of the Brooks Range of northern Alaska (Figure 1). Ore containing lead and zinc is milled at the Red Dog Mine to produce lead and zinc concentrates in a powder form. These concentrates are hauled year-round from Red Dog Mine via the DeLong Mountain Regional Transportation System (DMTS) road to concentrate storage buildings (CSBs) at the DMTS Port facility, where they are stored for later loading onto ships via a conveyor system during the summer months.

The port site is located 52 miles (by road) southwest of Red Dog Mine on the Chukchi Sea. Because the shipping season is confined to a few months when the waters are ice-free, the concentrates are stored at the port site for most of the year. Trucks haul the concentrates from the mine, along the DMTS road, and to the CSBs at the port. The CSBs are used to store the concentrates until shipping season begins. Enclosed conveyor belts transfer the concentrates from the CSBs to the barges, which are covered by fixed tarps. The barges carry the concentrates to deep-sea vessels 3 to 4 miles offshore, where they use a self-contained conveyor system to load the concentrates into the ships. Once the concentrates are loaded into the ships, they are delivered throughout North America, Europe, and Asia.

The DMTS Port facility includes the following features:

• Shallow-water dock

• Fueling/staging area

• Two CSBs and a truck unloading building (TUB)

• Road loop for trucks to enter and exit the CSBs

• Conveyors that transport ore concentrates from the TUB to the CSBs, and from the CSBs to the bargeloader conveyor at the dock

• Maintenance buildings

• Generator building

• Housing facilities for Teck Cominco Alaska Inc. (Teck Cominco) personnel at the personnel accommodation complex (PAC).

In the baseline port site monitoring program (PSMP) in June 1990, the port site was studied to determine “baseline” conditions prior to the shipping of concentrates. In 1991, the PSMP began to monitor lead, zinc, and diesel-range organic concentrations at the port site facilities. In 1992, Teck Cominco implemented mitigative measures to minimize fugitive lead and zinc. Onshore

\\bellevue1\docs\1900\8601997.001 1200\sap.doc 8601997.001 1200 0702 SS07 1

July 25, 2002

and marine water and sediment sample analyses were also added to the program in 1992. The program was replaced by an air monitoring program in 1997.

Teck Cominco also commissioned a characterization of sediments in the port area in 1998 as part of the DeLong Mountain Terminal Project. The purpose of this project was to investigate the feasibility of extending the dock and dredging a ship channel, to allow for direct loading of the concentrates onto the barges. The characterization specifically targeted the areas proposed for the dredge material disposal and for the dredge channel. The U.S. Army Corps of Engineers performed an additional sediment study in 2000.

The purpose of this sampling and analysis plan (SAP) is to evaluate the current extent of lead, zinc, and cadmium concentrate deposition in the vicinity of the DMTS port site. The sampling will include areas where metal concentrations may be elevated, including historical source areas and areas where materials and/or structures were temporarily stored or relocated. This SAP provides a protocol for screening lead, zinc, and cadmium levels in soil at the dock, conveyor areas, road loop, and miscellaneous buildings at the port site, as well as in surrounding tundra areas. Surface soil metals concentrations near selected port site features will be measured in the field using a portable x-ray fluorescence (XRF) detector and confirmed through laboratory analysis of a subset of samples. Tundra soils in areas surrounding the port site features will be collected and submitted for laboratory analysis. Water samples and sediment samples will be collected from four lagoons and the nearshore marine stations that were previously sampled in the PSMP. All sampling activities and laboratory work will be conducted in general accordance with the U.S. Environmental Protection Agency’s (EPA’s) Environmental Investigations, Standard Operating Procedure and Quality Assurance Manual (U.S. EPA 1997). Specific methods for performing field tasks are described in subsequent sections.

This SAP is organized into the following sections:

• Introduction

• Summary of Existing Port Site Data

• Port Site Sampling Program

• Equipment Decontamination

• Sample Identification System

• Field Data Reporting

• Analytical Methods

• Disposal of Investigation-Derived Waste

• Field Sampling Schedule

• References.


July 25, 2002

Sample locations are shown in figures at the end of the main text. In addition, EPA Method 6200 for field portable XRF spectrometry is provided in Appendix A, portable XRF operator qualifications and training are provided in Appendix B, and a standard operating procedure (SOP) for sample packaging and shipping is provided in Appendix C. The quality assurance project plan (QAPP) is provided separately (Exponent 2001).

Summary of Existing Port Site Data

Soil Data Data from the PSMP in 1996 are the most recent, and therefore the most representative of cumulative effects over the 1990−1996 period. In the 1996 program, 87 soil samples were taken near the CSB, 196 at the conveyor area, 40 at the dock area, 73 in the roadway area, 38 in the unloading area, and 39 in the fuel storage area. Table 1 shows the mean, median, and maximum concentrations of lead and zinc at each of the port facility areas.

The highest concentrations were observed in samples located close to operational features around the port site, and concentrations rapidly decline with distance. Figures 2 and 3 show the extent of lead and zinc concentration in the port facility area in 1996. Areas up to 500 ft from the conveyors, CSB, and roadway loop exceed the 1,000 ppm lead arctic zone soil cleanup level in Alaska Administrative Code, Section 18 AAC 75. Zinc concentrations exceeding the arctic zone soil cleanup level of 41,000 ppm were identified in three areas: two locations along the conveyor system and one location near the CSB and roadway loop.

Water Data In the 1996 PSMP, five unfiltered water samples were collected from each of the four lagoons (seven samples were collected from Port Lagoon South). Twenty-six unfiltered water samples were collected from the marine sampling station and one unfiltered water sample was collected from the control marine sampling station (Figure 4). Table 2 shows the mean, median, and maximum concentrations of lead and zinc at each of the water sampling stations.

Although the lead concentrations did not exceed the EPA water quality criteria for acute freshwater and saltwater aquatic life, some lagoon and marine water samples exceeded the lead criteria for chronic freshwater and saltwater aquatic life of 0.003 and 0.0085 mg/L, respectively (64 Fed. Reg. 19,781). Zinc concentrations in the lagoon water samples did not exceed the freshwater acute and chronic criteria of 0.12 and 0.11 mg/L, respectively. However, the maximum zinc concentration in the marine stations exceeded the saltwater acute and chronic criteria of 0.095 and 0.086 mg/L, respectively.

Sediment Data In the 1996 PSMP, sediment samples were collected in each of the four lagoons and in the nearshore marine zone. Five sediment samples were collected in each lagoon (with the


July 25, 2002

exception of seven samples from Port Lagoon South). Three sediment samples were obtained from the control marine station, and a total of 78 samples were taken from the nearshore marine zone stations (Figure 4). Table 3 shows the mean, median, and maximum concentrations of lead and zinc at each of the sediment sampling stations.

The maximum concentrations of lead in the lagoons and nearshore marine sediments did not exceed the Washington State Sediment Management Standard of 450 mg/kg (Ecology 2002). The maximum zinc concentration in the North Lagoon and both the maximum and mean concentrations in Port Lagoon North all exceeded the zinc standard of 410 mg/kg. The comparisons were made with Washington State standards because the State of Alaska has not established sediment criteria.

In 2000, Teck Cominco also characterized the marine sediment in the area of proposed dredging and dredged material disposal, as part of the Feasibility Stage of the DeLong Mountain Terminal Project. Sediments were collected at 23 stations: 9 in the proposed Channel and Turning Basin, 4 adjacent to the Loading Dock, and 10 in the proposed Marine Disposal area (locations nearest the shore are shown in Figure 4). The sediment samples were analyzed for metals, including lead, zinc, and cadmium.

The highest average lead concentration measured in sediment at the Loading Cell was 17.4 mg/kg, while the average in the proposed Channel was 8.9 mg/kg. Sediments collected from the proposed Marine Disposal area had average lead concentrations of 5.5 mg/kg. All sampled areas had similar zinc concentrations averaging 52.5 mg/kg. The maximum zinc concentration was 83 mg/kg in a Loading Cell sample. Cadmium concentrations among all the sampling locations averaged 2.0 mg/kg (Corps 2001). A comparison to the Washington State Sediment Management Standard of 450, 410, and 5.1 mg/kg for lead, zinc, and cadmium, respectively, indicates that the metals concentrations were below criteria. The lead and zinc concentrations in the nearshore marine sediments appeared to be lower in samples collected in 2000 than in samples collected during the 1996 PSMP.

Port Site Sampling Program The sampling program planned for summer 2002 includes soil, water, and sediment sampling. The protocols for this work will be described in detail in the following sections. Figure 5 shows the proposed soil, sediment, and water sampling stations, with detailed views in Figures 6 and 7.

Soil Sampling The soil sampling for this characterization study will include both soil samples analyzed by XRF, and soil samples collected for laboratory analysis. XRF measurements of lead, zinc, and cadmium concentrations at selected port facilities will be measured primarily in situ using a field portable XRF detector according to EPA Method 6200, Field Portable XRF Spectrometry for the Determination of Elemental Concentrations in Soil and Sediment, which is provided in Appendix A of this SAP. The locations planned for XRF sampling (Figures 6 and 7) include the two laydown areas that were historically used as temporary storage areas at the dock and racetrack roadway. XRF sampling will also be performed around the surge bin and in the


July 25, 2002

vicinity of the PAC building. In situ XRF analysis is a rapid testing method that can generate a large quantity of screening-level quality data over a short time period and allows field personnel to adapt the sampling strategy in reaction to XRF readings produced in real time. EPA Method 6200 recommends that at least 5 percent of XRF field measurements be confirmed through laboratory testing (see Appendix A). At 10 percent of the sampling stations, XRF measurements will be made ex situ on surface soil samples, which will then be submitted to the offsite laboratory for confirmatory analysis.

Sample soil cores will be sampled at the toe of the embankment at each of the road transects. Cores will be taken by hand with a hammer-driven split-spoon sampler. Each core will be at a depth of 1 ft below the surface. The core will be divided between a surface layer that consists of accumulated fines and fill material, and an organic matter layer that consists of peat and other naturally occurring soil material. Samples of the two layers of the soil core will be sent to an offsite laboratory for metals analyses.

Soil samples from the tundra, and from transects located along the racetrack, the road, the two CSBs, and the conveyor will be analyzed in an offsite laboratory. Lead, zinc, and cadmium will be analyzed by inductively coupled plasma analysis using EPA Method 6010B. Soil samples for XRF confirmation analysis and soil cores will also be analyzed by EPA Method 6010B. Blind field duplicate samples will be collected at 10 percent of the sampling locations. Additional discussion of analytical methods is provided in the Analytical Methods section below.

XRF Sampling Stations

• In situ XRF measurements will be recorded at approximately 125 stations at the port facility, as illustrated in Figures 6 and 7.

• Twelve stations will fall on a 200-ft spaced grid on the dock storage pad, which has historically been used as a temporary storage area (Figure 6).

• Forty-seven stations will fall on a 100-ft spaced grid oriented around the surge bin (which historically has been a source of fugitive dust), including the PAC area (Figure 6).

• Approximately 112 stations will fall on the CSB area grid. The area covered by this grid includes the laydown area east of CSB2 that has historically been used for temporary storage of equipment and material stockpiles, and it also includes the areas outside the doors of the CSBs (Figure 7).

• Five stations will located next to the TUB (Figure 7), in the area planned for an additional structure.

• Soils will also be collected at a minimum of 5 percent of the XRF stations, and sent to an offsite laboratory for confirmatory analysis, to comply with EPA Method 6200. For these soil stations, metals concentrations in surface soil samples will be determined by both in situ and ex situ XRF analyses and confirmed by laboratory analysis.


July 25, 2002

• If samples are deemed too moist for XRF analysis (at the discretion of the sampler), a soil sample will be collected and submitted for laboratory analysis.

• For the convenience of the field crew, station IDs and their locations are provided in Table 4. However, exact station locations will be determined in the field. Station coordinates will be recorded using a handheld global positioning system (GPS) receiver.

• Stations will be identified with a letter and number designation, based on their position on the grid or transect, as illustrated in Figures 6 and 7 and as discussed in the Sample Identification System section of this report.

General Procedures for XRF Analysis

• The field portable XRF detector will be operated and maintained in accordance with procedures outlined in the operator’s manual accompanying the instrument.

• A 15-minute warm-up period will precede any calibration, standardization, or operation of the XRF detector. The warm-up, calibration, standardization, and operation of the XRF detector will be performed in outside ambient air temperatures to avoid effects of temperature fluctuation.

• Calibration and standardization of the XRF detector will be performed according to the instrument manufacturer’s instructions and at a frequency consistent with the manufacturer’s recommendations.

• Field personnel will follow all quality assurance and quality control protocols defined in EPA Method 6200 (Appendix A), including energy calibration checks, blank samples analysis, calibration verification checks, precision sample analysis, calculation of site-specific method detection and quantitation limits, and collection of confirmatory samples.

• Field personnel will avoid calibrating, standardizing, or operating the XRF detector in the vicinity of an active computer monitor.

Procedures for In Situ XRF Analysis

• At each station, a location will be selected that is relatively flat and dry. Ideally, soil moisture content should be between 5 and 20 percent (see Appendix A).

• XRF sampling stations may be leveled with a clean stainless-steel spoon as necessary to accommodate the placement of the XRF detector and to remove unrepresentative debris.


July 25, 2002

• Three 60-second readings of lead, zinc, and cadmium concentrations will be collected at each sampling station. At 60 seconds, concentration and standard deviation measurements will be recorded in the field logbook, and in instrument memory for later downloading.

• Mean lead, zinc, and cadmium concentrations for each station will be calculated and recorded in the field logbook. The mean concentration will be the average of the XRF results obtained from three measurements per station.

• Information on the condition of the port site feature or facility, how recently it has been changed, and the moisture content (dry, moist, or wet) will be recorded in the field logbook for each sampling point.

Surface and Tundra Soil Sampling Stations Soil samples will be collected from both surface soils near port site facilities and from tundra soils. Surface soil consists of fill material near the port facilities. Two types of tundra soil samples will be collected. Shallow tundra soil samples will consist of peat or decaying organic matter beneath the vegetative cover, at the root zone. Deeper tundra soil samples will be collected at the top of the inorganic layer, if present, beneath the organic layer. Transects that extend from the port site facilities out toward the tundra may have both surface soil and tundra soil samples (Figure 8). Transects extending into the tundra will have additional stations at 250 and 500 ft.

• Approximately 144 shallow tundra soil sampling stations will be spaced 1,000 ft apart on a grid, beginning 100 ft away from port site features. This will provide greater coverage than the historical dustfall grid locations. At the sampler’s discretion, if the soil at stations near the lagoons is dry enough to be deemed a soil sample, a sample will be collected (Figure 5). Deep tundra samples will be collected at approximately 10 of these stations (5 near port site facilities, and 5 in outlying areas). The deep samples will be co-located with shallow samples to evaluate the occurrence of fugitive metals with depth.

• Sixty-four stations within 100 ft of the racetrack loop will be along bi-directional transects and spaced at 0, 10, and 50 ft from the feature in one direction, and 0, 10, 50, 250, and 500 ft in the direction toward the tundra (Figure 7). The two 0-ft stations will be at the toe of the embankment and will be core samples. Transects will be perpendicular to the orientation of the racetrack road and will be spaced approximately 500 ft from each other.

• Nine transects will be placed along the edges of the two CSBs. The 0-ft station will be located outside of the drainage ditches that surround the CSBs, as shown in Figure 8. Transects located on CSB1 extend into the tundra and will have stations at 250 and 500 ft added on (for a total of 35 stations). All transects will be spaced approximately 500 ft from each other, with one


July 25, 2002

transect extending out from the two northwest corners of each CSB (Figure 8).

• One hundred and forty-four stations within 100 ft of the conveyor system and road will be along bi-directional transects and spaced at 0, 10, 50, 250, and 500 ft from the conveyor or road, out towards the tundra, and spaced at 0, 10, and 50 ft in the opposite direction (Figure 8). The 0-ft stations on conveyor transects will be located directly below the outer edge of the conveyor on the surface of the foundation pad. The 0-ft station on road transects will be at the toe of embankment and will be soil core samples. Transects will be placed perpendicular to the orientation of the conveyor and road, and will be spaced approximately 500 ft from each other.

• For the convenience of the field crew, station IDs and their locations on the 1,000-ft grid are provided in Table 4. However, exact station locations will be determined in the field, as they are expected to vary based on field conditions. Station coordinates will be recorded using a handheld GPS receiver.

• Stations will be identified with a letter and number designation, based on their position on the grid or transect, as illustrated in Figures 5, 7, and 8, and as discussed in the Sample Identification System section of this report.

Procedures for Surface and Tundra Soil Sampling Soil samples collected for laboratory analyses will include surface soil samples and tundra soil samples. Surface soils (i.e., fill material) are found near port site facilities. Shallow tundra soils usually have a vegetation cover of mosses, lichens, or grasses. The tundra soil under the vegetation is peat or coarse, decaying organic material. Deep tundra soils are an inorganic layer of parent geologic material, where present.

• Surface soil samples will be taken at a depth of 0–1 in. from the surface.

• Shallow tundra soil samples will be taken at a depth 2−6 in. below the surface, depending on where the peat/organic material is present below the vegetation.

• If surface vegetation is present, it will be removed. The layer of peat or decaying organic matter beneath the vegetation will be collected as the shallow tundra soil sample.

• With a fresh set of gloves for each sample, the sampler will collect a handful of material and place it in a precleaned 8-oz sample container. As material is added to the jar, it will be compressed to squeeze out excess water. If a field duplicate is required at the station, soil will be split between two sample jars.

• Deep tundra soil samples will be collected by exposing the top of the inorganic soil layer, using a precleaned stainless steel spoon to sample the top


July 25, 2002

1−2 in. of the layer, and placing the sample into a precleaned 8-oz sample container. Where an inorganic layer is not found, a sample of organic tundra soil will be collected at a depth of approximately 1 ft below the shallow sample (above the permafrost).

• Each sample and field duplicate will be properly labeled with a unique sample identification number (see Sample Identification System section of this report) and submitted to the offsite analytical laboratory for analysis. Chain-of-custody forms will be completed and signed by the field representative and submitted with the samples to the analytical laboratory. Sample packaging and chain-of-custody procedures are provided in SOP 2 (Appendix C). Field documentation is discussed in the Field Data Reporting section of this report.

• Soil samples will be analyzed for lead, zinc, cadmium, and moisture content at an offsite laboratory.

• Information on the condition of the soil in the port area, and moisture content (dry, moist, or wet), will be recorded in the field logbook for each station.

Procedures for Ex Situ XRF Analysis

• XRF samples will be hand-collected with the same method used for surface soil samples. At each station, a sample will be collected and homogenized using a precleaned stainless-steel spoon and bowl.

• Approximately 5 g of homogenized soil will be placed in a clean 31.0-mm polyethylene sample cup (or equivalent) for XRF analysis. The sample cup will be filled at least one-half to three-quarters full and covered with 2.5 µm Mylar (or equivalent) film.

• Lead, zinc, and cadmium concentration data will be collected for 60 seconds by the XRF operator. At 60 seconds, concentration and standard deviation measurements will be recorded in the field logbook, and in instrument memory for later downloading.

• After XRF analysis, soil in the sample cup will be returned to the bowl and re-homogenized with the rest of the sample. The sample will then be transferred to a precleaned 8-oz jar. If a field duplicate is planned at the station, the re-homogenized soil will be split between two sample jars.

• Each sample and field duplicate will be properly labeled with a unique sample identification number and submitted to the offsite analytical laboratory for analysis. Chain-of-custody forms will be completed and signed by the field representative and submitted with the samples to the analytical laboratory. Sample packaging and chain-of-custody procedures are provided in SOP 2 (Appendix C). Field documentation is discussed in the Field Data Reporting section of this report.


July 25, 2002

• Soil samples will be analyzed for lead, zinc, cadmium, and moisture content at an offsite laboratory.

• Information on the condition of the soil in the port area and moisture content (dry, moist, or wet) will be recorded in the field logbook for each station.

Procedures for Soil Core Samples Soil cores will be collected from the toe of the embankment at each of 0-ft stations on road transects.

• The cores will be collected with a split-spoon sampler driven by a hand-operated power hammer. The split-spoon will be driven to a depth of 1 ft. Samples will be collected from two depth intervals: a surface sample, and an organic matter sample beneath the surface sample. The segregation of the two samples from the core will be at the discretion of the sampler.

• The surface sample will consist of accumulated fine-grained materials and fill materials. The organic matter sample will consist of peat or naturally occurring soil material.

• Each interval sample will be homogenized using a precleaned stainless-steel spoon and bowl, and a representative portion of the sample transferred to a precleaned 8-oz sample jar. If a field duplicate is required at the station, a representative portion of each homogenized sample will be placed into a second set of sample jars.

• Each sample and field duplicate will be properly labeled with a unique sample identification number (see Sample Identification System section of this report) and submitted to the offsite analytical laboratory for analysis. Chain-of-custody forms will be completed and signed by the field representative and submitted with the samples to the analytical laboratory. Sample packaging and chain-of-custody procedures are provided in SOP 2 (Appendix C). Field documentation is discussed in the Field Data Reporting section of this report.

• Core samples will be submitted for laboratory analysis for lead, zinc, and cadmium.

Water Sampling Water samples will be collected from the lagoons and submitted to an offsite laboratory for lead, zinc, and cadmium analysis. Stations will be identical to historical PSMP water sampling stations, however, marine water samples will not be collected. The water samples will be co-located with lagoon sediment samples (see Sediment Sampling section of this report). Water samples will be sent to an offsite laboratory for metals analyses. Lead will be analyzed by


July 25, 2002

graphite furnace atomic absorption spectrometry using EPA Method 7421, and zinc and cadmium will be analyzed by inductively coupled plasma analysis using EPA Method 6010B.

Description of Water Sampling Stations

• Two water samples will be taken in each of the four lagoons, which have been previously identified (from north to south) in the PSMP as North Lagoon, Port Lagoon North, Port Lagoon South, and Control Lagoon (Figure 5)

• In each lagoon, one water sample will be taken in a location closer to and one farther away from the port facility.

Procedures for Surface Water Sampling

• Field personnel in diving dry suits will wade out into the lagoon to the station location. Water samples will be collected before sediment samples are collected.

• Surface water sampling in the lagoons will be collected by vertically submersing a precleaned 1-L polyethylene sample bottle below the water surface and allowing only the upper portion of the water to enter.

• Water samples for dissolved metal analysis will be collected in a separate bottle, filtered through a 0.45 µm filter into a precleaned disposable flask, and transferred to another sample bottle.

• Both filtered and unfiltered water samples will be preserved with 2 mL of HNO3 after collection.

• Each sample and field duplicate will be properly labeled with a unique sample identification number (identical to PSMP identification numbers) and submitted to the offsite analytical laboratory for analysis. Chain-of-custody forms will be completed and signed by the field representative and submitted with the samples to the analytical laboratory. Sample packaging and chain-of-custody procedures are provided in SOP 2 (Appendix C). Field documentation is discussed in the Field Data Reporting section of this report.

• At each water sample station, conductivity, pH, and temperature readings will be collected with a field meter to describe the basic properties of the waters sampled.

• Station IDs and locations from the PSMP can be found in Table 5. This table is provided for the convenience of the field crew, but it is expected that exact locations will vary, depending on the field conditions. Station coordinates will be recorded using a handheld GPS receiver.


July 25, 2002

Sediment Sampling Sediment samples will be collected and sent to an offsite laboratory for lead, zinc, and cadmium analysis. Sediment samples will be obtained by a team member or a diver (at stations with large depths) using a hand-held sample container. Some of the sediment samples to be collected in the lagoons will have co-located water samples (see Figure 5 and the Water Sampling section of this report). The samples will be sent to an offsite laboratory for metals analyses. Lead, zinc, and cadmium will be analyzed by inductively coupled plasma analysis using EPA Method 6010B.

Description of Sediment Sampling Stations

• Twenty-six sediment samples will be taken in the nearshore marine waters at the port site. Locations of these sediment samples will be identical to sediment samples taken in the PSMP (Figure 5).

• Twenty-two sediment samples will be taken in the four onshore lagoons. Locations of these sediment samples will be identical to sediment samples taken in the PSMP (Figure 5).

• Three sediment samples will be taken from the drainage ditch surrounding CSB1. Ditch sample locations shown in Figure 7 are approximate and may be adjusted based on field conditions.

Procedures for Sediment Sampling

• Field personnel will don a diving dry suit and a breathing apparatus (when necessary in deep waters) to collect the sediment samples. Personnel should ensure that the fine sediments on the surface are not stirred up or disturbed.

• Personnel will uncap the sampling jar and use it to skim along the sediment surface (until the jar is full) to obtain the top 2 cm of sediment. The lid will be immediately replaced, being careful not to lose any fine sediment.

• The collection jar will be a precleaned 4-oz glass jar with Teflon® lid. The collection jar will also become the sample container.

• Alternatively, sediment samples may be collected in the winter by coring through the ice and using a Shelby tube to collect the sediment sample. If this approach is taken, a separate sampling procedure will be provided in a document to follow.

• The sample container will be properly labeled with a unique sample identification number (identical to the PSMP identification number) and submitted to the offsite analytical laboratory for analysis.

• Station IDs and locations from the PSMP can be found in Table 5. This table is provided for the convenience of the field crew but it is expected that exact


July 25, 2002

locations will vary, depending on the field conditions. Station coordinates will be recorded using a handheld GPS receiver.

• Chain-of-custody forms will be completed and signed by the field representative and submitted with the samples to the analytical laboratory. Sample packaging and chain-of-custody procedures are provided in SOP 2 (Appendix C). Field documentation is discussed in the Field Data Reporting section of this report.

• Sediment pH levels will be taken for each sediment sample and recorded.

Equipment Decontamination All reusable sampling equipment will be decontaminated prior to collection of each sample. Procedures for management and disposal of waste generated during equipment decontamination are described in the Disposal of Investigation-Derived Waste section of this report.

Sampling equipment (such as stainless-steel spoons, bowls, and split-spoon samplers) will be washed using a scrub brush in a solution of Alconox® and water. Following the wash, equipment will be rinsed in tap water and then rinsed with deionized or distilled water.

Equipment rinsate blanks will be used to help identify possible contamination from the sampling environment and/or from decontaminated sampling equipment. Equipment rinsate blanks will be prepared at least once per sampling event per the type of sampling equipment used. Equipment rinsate blanks will be prepared by pouring laboratory distilled/deionized water through, over, and into the decontaminated sample collection equipment, then transferring the water to the laboratory-prepared sample containers. Each blank will be assigned a unique sample number and submitted to the offsite laboratory for analysis. Equipment rinsate blanks will be analyzed for lead, zinc, and cadmium.

Field blanks will be collected at a minimum frequency of once per day in order to evaluate potential background concentrations present in the air and in the distilled/deionized water used for the final decontamination rinse. Field blanks will be prepared at the sample collection site by filling the laboratory-prepared sample bottle with distilled/deionized water, sealing the bottle, assigning a unique sample number to the field blank, and submitting the bottle to the offsite laboratory for analysis. Field blanks will be analyzed for lead, zinc, and cadmium.

Sample Identification System Each sample and field duplicate will be assigned a unique sample number. Soil samples will be named based on their grid location, as illustrated in Figures 5, 6, and 7. Water and sediment samples will have the same sample identities as the PSMP (see Table 5). Transects will be numbered in sequential order in the field. Bi-directional transects will be numbered individually. Field duplicates (to be collected at 10 percent of the sample stations) will be


July 25, 2002

identified in the same way, except that the station number will be a number beyond the expected range of actual station numbering. Samples will be identified using the following nomenclature:

PG-A1, PG-A2, PG-A3, … = Tundra soil on the 1,000-ft port grid, collected for laboratory analysis recorded for a station based on its location on the grid (Table 4).

RAT1-0, RAT1-10, RAT1-50, … = Soil sample collected from racetrack transect, numbered sequentially in the field. A suffix of 0, 10, or 50 will be added to identify individual stations at 0, 10, and 50 ft.

ROT1-0, ROT1-10, ROT1-50, … = Soil samples collected from road transects, numbered sequentially in the field. A suffix of 0, 10, 50, 250, or 500 will be added to identify individual stations at 0, 10, 50, 250, and 500 ft.

CVT1-0, CVT1-10, CVT1-50, … = Soil samples collected from conveyor transects, numbered sequentially in the field. A suffix of 0, 10, 50, 250, or 500 will be added to identify individual stations at 0, 10, 50, 250, and 500 ft.

C1T1-0, C1T1-10, C1T1-50, … = Soil samples collected from CSB1 transects, numbered sequentially in the field. A suffix of 0, 10, 50, 250, or 500 will be added to identify individual stations at 0, 10, 50, 250, and 500 ft.

DD1, DD2, DD3, … = Sediment samples collected from the drainage ditch around CSB1, numbered sequentially in the field.

DSP-A1-A, DSP-A1-B, … = In situ XRF analysis recorded for dock storage pad stations, including areas around the surge bin and PAC stations, based on its location on the grid (a suffix of A, B, or C will be added to identify the three individual measurements recorded at that station) (Table 4).

CAG-A1-A, CAG-A1-B, … = In situ XRF analysis recorded for CSB area grid stations, based on their location on the grid (a suffix of A, B, or C will be added to identify the three individual measurements recorded at that station) (Table 4).

TU-1, TU-2, TU-3, … = In situ XRF analysis recorded for TUB stations; stations will be numbered sequentially in the field.

RB-1, RB-2, … = Rinsate blank sample.

FB-1, FB-2, … = Field blank sample.


July 25, 2002

Water and sediment samples will be identified like the original nomenclature in the PSMP (RWJ 1997). Station IDs and locations are provided in Table 5.

Field Data Reporting Sampling activities will be documented in a bound, waterproof field logbook, or on field forms. All daily field activities will be documented in indelible ink in the logbook or on the forms, and no erasures will be made. All corrections will consist of a single line-out deletion, followed by the sampler’s initials and the date. Detailed information to be recorded in the logbook or on the forms will include:

• XRF measurements for lead, zinc, and cadmium taken at individual sampling points, as well as mean XRF measurements calculated for stations

• Date and time of sample collection or XRF measurement

• Sample number (as described in previous section)

• Cross-references of numbers for duplicate samples

• Location of sample, including station name, distance from the associated port facility, GPS coordinates, and a sketch of the transect in relation to the associated port feature

• Sample type (i.e., surface soil, tundra soil, XRF)

• Sample material description

• Unique sample tag number

• Date and time of equipment calibration

• Description of the sample, moisture content of soil (dry, moist, or wet)

• Weather conditions

• Description of any deviation from the SAP (as applicable)

• Personnel conducting the activity. Any other pertinent data or observations identified during sampling will also be recorded. Quality assurance and quality control documentation, including sample labels and chain-of-custody forms, will be completed. Samples will be delivered to the offsite analytical laboratory using standard chain-of-custody procedures.


July 25, 2002

Analytical Methods Surface soil metals concentrations will be measured in the field by XRF analysis following EPA Method 6200. Surface soil, tundra soil, and core samples that are submitted to the offsite laboratory will be tested for total lead, zinc, and cadmium. Lead, zinc, and cadmium in soil will be measured by inductively coupled plasma analysis using EPA Method 6010B. Zinc and cadmium in water will also be analyzed with Method 6010B. Lead in water will be quantified by graphite furnace atomic absorption spectrometry using EPA Method 7421. Analytical methods, detection limits, and sample volume requirements are summarized in the QAPP (Exponent 2001).

Disposal of Investigation-Derived Waste Wastes generated during the sampling program are expected to be non-hazardous. Investigation-derived waste (IDW) generated during sampling is expected to include disposable XRF sample cups and Mylar film, decontamination water containing residual solid materials, and used personal protective equipment (e.g., gloves, paper towels). Liquid IDW generated from decontamination will be disposed of on the road surface or in the mine or port site wastewater treatment systems. Solid IDW (e.g., used personal protective equipment) will be placed in plastic garbage bags and disposed of at the Red Dog Mine or at the port solid waste collection facilities.

Field Sampling Schedule The field effort is expected to begin in late June 2002 and should be completed within 2 to 3 weeks.

References Corps. 2001. Pre-dredge sediment characterization DeLong Mountain Terminal Project, Red Dog, Alaska, August 2000. Draft. U.S. Army Corps of Engineers, Alaska District, Engineering Services Branch, Materials Section.

Ecology. 2002. http://www.ecy.wa.gov/programs/tcp/smu/sed_chem.htm.

Exponent. 2001. Quality assurance project plan, haul road fugitive dust study, Red Dog Mine, Alaska. Prepared for Teck Cominco Alaska Inc., Anchorage, AK. Exponent, Bellevue, WA.

RWJ. 1997. Red Dog port site monitoring program. August 1996 Final Report. Prepared for Cominco Alaska, Inc., Kotzebue, AK. RWJ Consulting.

U.S. EPA. 1997. Environmental investigations, standard operating procedure and quality assurance manual. U.S. Environmental Protection Agency, Washington, DC.


Appendix A EPA Method 6200

CD-ROM 6200 - 1 Revision 0January 1998

METHOD 6200

FIELD PORTABLE X-RAY FLUORESCENCE SPECTROMETRY FOR THEDETERMINATION OF ELEMENTAL CONCENTRATIONS IN SOIL AND SEDIMENT

1.0 SCOPE AND APPLICATION

1.1 This method is applicable to the in situ and intrusive analysis of the 26 analytes listedin Table 1 for soil and sediment samples. Some common elements are not listed in Table 1 becausethey are considered "light" elements that cannot be detected by field portable x-ray fluorescence(FPXRF). They are: lithium, beryllium, sodium, magnesium, aluminum, silicon, and phosphorus.Most of the analytes listed in Table 1 are of environmental concern, while a few others haveinterference effects or change the elemental composition of the matrix, affecting quantitation of theanalytes of interest. Generally elements of atomic number 16 or greater can be detected andquantitated by FPXRF.

1.2 Detection limits depend on several factors, the analyte of interest, the type of detectorused, the type of excitation source, the strength of the excitation source, count times used toirradiate the sample, physical matrix effects, chemical matrix effects, and interelement spectralinterferences. General instrument detection limits for analytes of interest in environmentalapplications are shown in Table 1. These detection limits apply to a clean matrix of quartz sand(silicon dioxide) free of interelement spectral interferences using long (600-second) count times.These detection limits are given for guidance only and will vary depending on the sample matrix,which instrument is used, and operating conditions. A discussion of field performance-baseddetection limits is presented in Section 13.4 of this method. The clean matrix and field performance-based detection limits should be used for general planning purposes, and a third detection limitdiscussed, based on the standard deviation around single measurements, should be used inassessing data quality. This detection limit is discussed in Sections 9.7 and 11.3.

1.3 Use of this method is restricted to personnel either trained and knowledgeable in theoperation of an XRF instrument or under the supervision of a trained and knowledgeable individual.This method is a screening method to be used with confirmatory analysis using EPA-approvedmethods. This method’s main strength is as a rapid field screening procedure. The methoddetection limits (MDL) of FPXRF are above the toxicity characteristic regulatory level for most RCRAanalytes. If the precision, accuracy, and detection limits of FPXRF meet the data quality objectives(DQOs) of your project, then XRF is a fast, powerful, cost effective technology for sitecharacterization.

2.0 SUMMARY OF METHOD

2.1 The FPXRF technologies described in this method use sealed radioisotope sources toirradiate samples with x-rays. X-ray tubes are used to irradiate samples in the laboratory and arebeginning to be incorporated into field portable instruments. When a sample is irradiated with x-rays,the source x-rays may undergo either scattering or absorption by sample atoms. This later processis known as the photoelectric effect. When an atom absorbs the source x-rays, the incident radiationdislodges electrons from the innermost shells of the atom, creating vacancies. The electronvacancies are filled by electrons cascading in from outer electron shells. Electrons in outer shellshave higher energy states than inner shell electrons, and the outer shell electrons give off energyas they cascade down into the inner shell vacancies. This rearrangement of electrons results inemission of x-rays characteristic of the given atom. The emission of x-rays, in this manner, is termedx-ray fluorescence.


Three electron shells are generally involved in emission of x-rays during FPXRF analysis ofenvironmental samples: the K, L, and M shells. A typical emission pattern, also called an emissionspectrum, for a given metal has multiple intensity peaks generated from the emission of K, L, or Mshell electrons. The most commonly measured x-ray emissions are from the K and L shells; onlymetals with an atomic number greater than 57 have measurable M shell emissions.

Each characteristic x-ray line is defined with the letter K, L, or M, which signifies which shellhad the original vacancy and by a subscript alpha (") or beta ($), which indicates the higher shellfrom which electrons fell to fill the vacancy and produce the x-ray. For example, a K line is"produced by a vacancy in the K shell filled by an L shell electron, whereas a K line is produced by$a vacancy in the K shell filled by an M shell electron. The K transition is on average 6 to 7 times"more probable than the K transition; therefore, the K line is approximately 7 times more intense$ "than the K line for a given element, making the K line the choice for quantitation purposes.$ "

The K lines for a given element are the most energetic lines and are the preferred lines foranalysis. For a given atom, the x-rays emitted from L transitions are always less energetic thanthose emitted from K transitions. Unlike the K lines, the main L emission lines (L and L ) for an" $element are of nearly equal intensity. The choice of one or the other depends on what interferingelement lines might be present. The L emission lines are useful for analyses involving elements ofatomic number (Z) 58 (cerium) through 92 (uranium).

An x-ray source can excite characteristic x-rays from an element only if the source energy isgreater than the absorption edge energy for the particular line group of the element, that is, the Kabsorption edge, L absorption edge, or M absorption edge energy. The absorption edge energy issomewhat greater than the corresponding line energy. Actually, the K absorption edge energy isapproximately the sum of the K, L, and M line energies of the particular element, and the Labsorption edge energy is approximately the sum of the L and M line energies. FPXRF is moresensitive to an element with an absorption edge energy close to but less than the excitation energyof the source. For example, when using a cadmium-109 source, which has an excitation energy of22.1 kiloelectron volts (keV), FPXRF would exhibit better sensitivity for zirconium which has a K lineenergy of 15.7 keV than to chromium, which has a K line energy of 5.41 keV.

2.2 Under this method, inorganic analytes of interest are identified and quantitated usinga field portable energy-dispersive x-ray fluorescence spectrometer. Radiation from one or moreradioisotope sources or an electrically excited x-ray tube is used to generate characteristic x-rayemissions from elements in a sample. Up to three sources may be used to irradiate a sample. Eachsource emits a specific set of primary x-rays that excite a corresponding range of elements in asample. When more than one source can excite the element of interest, the source is selectedaccording to its excitation efficiency for the element of interest.

For measurement, the sample is positioned in front of the probe window. This can be donein two manners using FPXRF instruments: in situ or intrusive. If operated in the in situ mode, theprobe window is placed in direct contact with the soil surface to be analyzed. When an FPXRFinstrument is operated in the intrusive mode, a soil or sediment sample must be collected, prepared,and placed in a sample cup. The sample cup is then placed on top of the window inside a protectivecover for analysis.

Sample analysis is then initiated by exposing the sample to primary radiation from the source.Fluorescent and backscattered x-rays from the sample enter through the detector window and areconverted into electric pulses in the detector. The detector in FPXRF instruments is usually eithera solid-state detector or a gas-filled proportional counter. Within the detector, energies of thecharacteristic x-rays are converted into a train of electric pulses, the amplitudes of which are linearly


proportional to the energy of the x-rays. An electronic multichannel analyzer (MCA) measures thepulse amplitudes, which is the basis of qualitative x-ray analysis. The number of counts at a givenenergy per unit of time is representative of the element concentration in a sample and is the basisfor quantitative analysis. Most FPXRF instruments are menu-driven from software built into the unitsor from personal computers (PC).

The measurement time of each source is user-selectable. Shorter source measurement times(30 seconds) are generally used for initial screening and hot spot delineation, and longermeasurement times (up to 300 seconds) are typically used to meet higher precision and accuracyrequirements.

FPXRF instruments can be calibrated using the following methods: internally usingfundamental parameters determined by the manufacturer, empirically based on site-specificcalibration standards (SSCS), or based on Compton peak ratios. The Compton peak is producedby backscattering of the source radiation. Some FPXRF instruments can be calibrated using multiplemethods.

3.0 DEFINITIONS

3.1 FPXRF: Field portable x-ray fluorescence.

3.2 MCA: Multichannel analyzer for measuring pulse amplitude.

3.3 SSCS: Site specific calibration standard.

3.4 FP: Fundamental parameter.

3.5 ROI: Region of interest.

3.6 SRM: Standard reference material. A standard containing certified amounts of metalsin soil or sediment.

3.7 eV: Electron Volt. A unit of energy equivalent to the amount of energy gained by anelectron passing through a potential difference of one volt.

3.8 Refer to Chapter One and Chapter Three for additional definitions.

4.0 INTERFERENCES

4.1 The total method error for FPXRF analysis is defined as the square root of the sum ofsquares of both instrument precision and user- or application-related error. Generally, instrumentprecision is the least significant source of error in FPXRF analysis. User- or application-related erroris generally more significant and varies with each site and method used. Some sources ofinterference can be minimized or controlled by the instrument operator, but others cannot. Commonsources of user- or application-related error are discussed below.

4.2 Physical matrix effects result from variations in the physical character of the sample.These variations may include such parameters as particle size, uniformity, homogeneity, and surfacecondition. For example, if any analyte exists in the form of very fine particles in a coarser-grainedmatrix, the analyte’s concentration measured by the FPXRF will vary depending on how fine particlesare distributed within the coarser-grained matrix. If the fine particles "settle" to the bottom of thesample cup, the analyte concentration measurement will be higher than if the fine particles are not


mixed in well and stay on top of the coarser-grained particles in the sample cup. One way to reducesuch error is to grind and sieve all soil samples to a uniform particle size thus reducing sample-to-sample particle size variability. Homogeneity is always a concern when dealing with soil samples.Every effort should be made to thoroughly mix and homogenize soil samples before analysis. Fieldstudies have shown heterogeneity of the sample generally has the largest impact on comparabilitywith confirmatory samples.

4.3 Moisture content may affect the accuracy of analysis of soil and sediment sampleanalyses. When the moisture content is between 5 and 20 percent, the overall error from moisturemay be minimal. However, moisture content may be a major source of error when analyzingsamples of surface soil or sediment that are saturated with water. This error can be minimized bydrying the samples in a convection or toaster oven. Microwave drying is not recommended becausefield studies have shown that microwave drying can increase variability between FPXRF data andconfirmatory analysis and because metal fragments in the sample can cause arcing to occur in amicrowave.

4.4 Inconsistent positioning of samples in front of the probe window is a potential sourceof error because the x-ray signal decreases as the distance from the radioactive source increases.This error is minimized by maintaining the same distance between the window and each sample.For the best results, the window of the probe should be in direct contact with the sample, whichmeans that the sample should be flat and smooth to provide a good contact surface.

4.5 Chemical matrix effects result from differences in the concentrations of interferingelements. These effects occur as either spectral interferences (peak overlaps) or as x-rayabsorption and enhancement phenomena. Both effects are common in soils contaminated withheavy metals. As examples of absorption and enhancement effects; iron (Fe) tends to absorbcopper (Cu) x-rays, reducing the intensity of the Cu measured by the detector, while chromium (Cr)will be enhanced at the expense of Fe because the absorption edge of Cr is slightly lower in energythan the fluorescent peak of iron. The effects can be corrected mathematically through the use offundamental parameter (FP) coefficients. The effects also can be compensated for using SSCS,which contain all the elements present on site that can interfere with one another.

4.6 When present in a sample, certain x-ray lines from different elements can be very closein energy and, therefore, can cause interference by producing a severely overlapped spectrum. Thedegree to which a detector can resolve the two different peaks depends on the energy resolution ofthe detector. If the energy difference between the two peaks in electron volts is less than theresolution of the detector in electron volts, then the detector will not be able to fully resolve thepeaks.

The most common spectrum overlaps involve the K line of element Z-1 with the K line of$ "element Z. This is called the K /K interference. Because the K :K intensity ratio for a given" $ " $element usually is about 7:1, the interfering element, Z-1, must be present at large concentrationsto cause a problem. Two examples of this type of spectral interference involve the presence of largeconcentrations of vanadium (V) when attempting to measure Cr or the presence of largeconcentrations of Fe when attempting to measure cobalt (Co). The V K and K energies are 4.95" $and 5.43 keV, respectively, and the Cr K energy is 5.41 keV. The Fe K and K energies are 6.40" " $and 7.06 keV, respectively, and the Co K energy is 6.92 keV. The difference between the V K and" $Cr K energies is 20 eV, and the difference between the Fe K and the Co K energies is 140 eV." $ "The resolution of the highest-resolution detectors in FPXRF instruments is 170 eV. Therefore, largeamounts of V and Fe will interfere with quantitation of Cr or Co, respectively. The presence of Feis a frequent problem because it is often found in soils at tens of thousands of parts per million(ppm).


4.7 Other interferences can arise from K/L, K/M, and L/M line overlaps, although theseoverlaps are less common. Examples of such overlap involve arsenic (As) K /lead (Pb) L and sulfur" "(S) K /Pb M . In the As/Pb case, Pb can be measured from the Pb L line, and As can be measured" " $from either the As K or the As K line; in this way the interference can be corrected. If the As K" ß $line is used, sensitivity will be decreased by a factor of two to five times because it is a less intenseline than the As K line. If the As K line is used in the presence of Pb, mathematical corrections" "within the instrument software can be used to subtract out the Pb interference. However, becauseof the limits of mathematical corrections, As concentrations cannot be efficiently calculated forsamples with Pb:As ratios of 10:1 or more. This high ratio of Pb to As may result in no As beingreported regardless of the actual concentration present.

No instrument can fully compensate for this interference. It is important for an operator tounderstand this limitation of FPXRF instruments and consult with the manufacturer of the FPXRFinstrument to evaluate options to minimize this limitation. The operator’s decision will be based onaction levels for metals in soil established for the site, matrix effects, capabilities of the instrument,data quality objectives, and the ratio of lead to arsenic known to be present at the site. If a site isencountered that contains lead at concentrations greater than ten times the concentration of arsenicit is advisable that all critical soil samples be sent off site for confirmatory analysis by an EPA-approved method.

4.8 If SSCS are used to calibrate an FPXRF instrument, the samples collected must berepresentative of the site under investigation. Representative soil sampling ensures that a sampleor group of samples accurately reflects the concentrations of the contaminants of concern at a giventime and location. Analytical results for representative samples reflect variations in the presence andconcentration ranges of contaminants throughout a site. Variables affecting samplerepresentativeness include differences in soil type, contaminant concentration variability, samplecollection and preparation variability, and analytical variability, all of which should be minimized asmuch as possible.

4.9 Soil physical and chemical effects may be corrected using SSCS that have beenanalyzed by inductively coupled plasma (ICP) or atomic absorption (AA) methods. However, a majorsource of error can be introduced if these samples are not representative of the site or if theanalytical error is large. Another concern is the type of digestion procedure used to prepare the soilsamples for the reference analysis. Analytical results for the confirmatory method will varydepending on whether a partial digestion procedure, such as SW-846 Method 3050, or a totaldigestion procedure, such as Method 3052 is used. It is known that depending on the nature of thesoil or sediment, Method 3050 will achieve differing extraction efficiencies for different analytes ofinterest. The confirmatory method should meet the project data quality objectives.

XRF measures the total concentration of an element; therefore, to achieve the greatestcomparability of this method with the reference method (reduced bias), a total digestion procedureshould be used for sample preparation. However, in the study used to generate the performancedata for this method, the confirmatory method used was Method 3050, and the FPXRF datacompared very well with regression correlation coefficients (r often exceeding 0.95, except for2

barium and chromium. See Table 9 in Section 17.0). The critical factor is that the digestionprocedure and analytical reference method used should meet the data quality objectives (DQOs) ofthe project and match the method used for confirmation analysis.

4.10 Ambient temperature changes can affect the gain of the amplifiers producing instrumentdrift. Gain or drift is primarily a function of the electronics (amplifier or preamplifier) and not thedetector as most instrument detectors are cooled to a constant temperature. Most FPXRFinstruments have a built-in automatic gain control. If the automatic gain control is allowed to make


periodic adjustments, the instrument will compensate for the influence of temperature changes onits energy scale. If the FPXRF instrument has an automatic gain control function, the operator willnot have to adjust the instrument’s gain unless an error message appears. If an error messageappears, the operator should follow the manufacturer’s procedures for troubleshooting the problem.Often, this involves performing a new energy calibration. The performance of an energy calibrationcheck to assess drift is a quality control measure discussed in Section 9.2.

If the operator is instructed by the manufacturer to manually conduct a gain check because ofincreasing or decreasing ambient temperature, it is standard to perform a gain check after every 10to 20 sample measurements or once an hour whichever is more frequent. It is also suggested thata gain check be performed if the temperature fluctuates more than 10 to 20EF. The operator shouldfollow the manufacturer’s recommendations for gain check frequency.

5.0 SAFETY

5.1 Proper training for the safe operation of the instrument and radiation training should becompleted by the analyst prior to analysis. Radiation safety for each specific instrument can befound in the operators manual. Protective shielding should never be removed by the analyst or anypersonnel other than the manufacturer. The analyst should be aware of the local state and nationalregulations that pertain to the use of radiation-producing equipment and radioactive materials withwhich compliance is required. Licenses for radioactive materials are of two types; (1) general licensewhich is usually provided by the manufacturer for receiving, acquiring, owning, possessing, using,and transferring radioactive material incorporated in a device or equipment, and (2) specific licensewhich is issued to named persons for the operation of radioactive instruments as required by localstate agencies. There should be a person appointed within the organization that is solelyresponsible for properly instructing all personnel, maintaining inspection records, and monitoring x-ray equipment at regular intervals. A copy of the radioactive material licenses and leak tests shouldbe present with the instrument at all times and available to local and national authorities uponrequest. X-ray tubes do not require radioactive material licenses or leak tests, but do requireapprovals and licenses which vary from state to state. In addition, fail-safe x-ray warning lightsshould be illuminated whenever an x-ray tube is energized. Provisions listed above concerningradiation safety regulations, shielding, training, and responsible personnel apply to x-ray tubes justas to radioactive sources. In addition, a log of the times and operating conditions should be keptwhenever an x-ray tube is energized. Finally, an additional hazard present with x-ray tubes is thedanger of electric shock from the high voltage supply. The danger of electric shock is as substantialas the danger from radiation but is often overlooked because of its familiarity.

5.2 Radiation monitoring equipment should be used with the handling of the instrument.The operator and the surrounding environment should be monitored continually for analyst exposureto radiation. Thermal luminescent detectors (TLD) in the form of badges and rings are used tomonitor operator radiation exposure. The TLDs should be worn in the area of most frequentexposure. The maximum permissible whole-body dose from occupational exposure is 5 RoentgenEquivalent Man (REM) per year. Possible exposure pathways for radiation to enter the body areingestion, inhaling, and absorption. The best precaution to prevent radiation exposure is distanceand shielding.

5.3 Refer to Chapter Three for guidance on some proper safety protocols.

6.0 EQUIPMENT AND SUPPLIES

6.1 FPXRF Spectrometer: An FPXRF spectrometer consists of four major components:(1) a source that provides x-rays; (2) a sample presentation device; (3) a detector that converts x-


ray-generated photons emitted from the sample into measurable electronic signals; and (4) a dataprocessing unit that contains an emission or fluorescence energy analyzer, such as an MCA, thatprocesses the signals into an x-ray energy spectrum from which elemental concentrations in thesample may be calculated, and a data display and storage system. These components andadditional, optional items, are discussed below.

6.1.1 Excitation Sources: Most FPXRF instruments use sealed radioisotope sourcesto produce x-rays in order to irradiate samples. The FPXRF instrument may contain betweenone and three radioisotope sources. Common radioisotope sources used for analysis formetals in soils are iron (Fe)-55, cadmium (Cd)-109, americium (Am)-241, and curium (Cm)-244. These sources may be contained in a probe along with a window and the detector; theprobe is connected to a data reduction and handling system by means of a flexible cable.Alternatively, the sources, window, and detector may be included in the same unit as the datareduction and handling system.

The relative strength of the radioisotope sources is measured in units of millicuries(mCi). All other components of the FPXRF system being equal, the stronger the source, thegreater the sensitivity and precision of a given instrument. Radioisotope sources undergoconstant decay. In fact, it is this decay process that emits the primary x-rays used to excitesamples for FPXRF analysis. The decay of radioisotopes is measured in "half-lives." The half-life of a radioisotope is defined as the length of time required to reduce the radioisotopesstrength or activity by half. Developers of FPXRF technologies recommend sourcereplacement at regular intervals based on the source's half-life. The characteristic x-raysemitted from each of the different sources have energies capable of exciting a certain rangeof analytes in a sample. Table 2 summarizes the characteristics of four common radioisotopesources.

X-ray tubes have higher radiation output, no intrinsic lifetime limit, produce constantoutput over their lifetime, and do not have the disposal problems of radioactive sources but arejust now appearing in FPXRF instruments An electrically-excited x-ray tube operates bybombarding an anode with electrons accelerated by a high voltage. The electrons gain anenergy in electron volts equal to the accelerating voltage and can excite atomic transitions inthe anode, which then produces characteristic x-rays. These characteristic x-rays are emittedthrough a window which contains the vacuum required for the electron acceleration. Animportant difference between x-ray tubes and radioactive sources is that the electrons whichbombard the anode also produce a continuum of x-rays across a broad range of energies inaddition to the characteristic x-rays. This continuum is weak compared to the characteristicx-rays but can provide substantial excitation since it covers a broad energy range. It has theundesired property of producing background in the spectrum near the analyte x-ray lines whenit is scattered by the sample. For this reason a filter is often used between the x-ray tube andthe sample to suppress the continuum radiation while passing the characteristic x-rays fromthe anode. This filter is sometimes incorporated into the window of the x-ray tube. The choiceof accelerating voltage is governed by the anode material, since the electrons must havesufficient energy to excite the anode, which requires a voltage greater than the absorptionedge of the anode material. The anode is most efficiently excited by voltages 2 to 2.5 timesthe edge energy (most x-rays per unit power to the tube), although voltages as low as 1.5times the absorption edge energy will work. The characteristic x-rays emitted by the anode arecapable of exciting a range of elements in the sample just as with a radioactive source. Table3 gives the recommended operating voltages and the sample elements excited for somecommon anodes.


6.1.2 Sample Presentation Device: FPXRF instruments can be operated in twomodes: in situ and intrusive. If operated in the in situ mode, the probe window is placed indirect contact with the soil surface to be analyzed. When an FPXRF instrument is operatedin the intrusive mode, a soil or sediment sample must be collected, prepared, and placed ina sample cup. For most FPXRF instruments operated in the intrusive mode, the probe isrotated so that the window faces upward. A protective sample cover is placed over thewindow, and the sample cup is placed on top of the window inside the protective sample coverfor analysis.

6.1.3 Detectors: The detectors in the FPXRF instruments can be either solid-statedetectors or gas-filled, proportional counter detectors. Common solid-state detectors includemercuric iodide (HgI ), silicon pin diode and lithium-drifted silicon Si(Li). The HgI detector is2 2operated at a moderately subambient temperature controlled by a low power thermoelectriccooler. The silicon pin diode detector also is cooled via the thermoelectric Peltier effect. TheSi(Li) detector must be cooled to at least -90 EC either with liquid nitrogen or by thermoelectriccooling via the Peltier effect. Instruments with a Si(Li) detector have an internal liquid nitrogendewar with a capacity of 0.5 to 1.0 liter. Proportional counter detectors are rugged andlightweight, which are important features of a field portable detector. However, the resolutionof a proportional counter detector is not as good as that of a solid-state detector. The energyresolution of a detector for characteristic x-rays is usually expressed in terms of full width athalf-maximum (FWHM) height of the manganese K peak at 5.89 keV. The typical resolutions"of the above mentioned detectors are as follows: HgI -270 eV; silicon pin diode-250 eV;2Si(Li)–170 eV; and gas-filled, proportional counter-750 eV.

During operation of a solid-state detector, an x-ray photon strikes a biased, solid-statecrystal and loses energy in the crystal by producing electron-hole pairs. The electric chargeproduced is collected and provides a current pulse that is directly proportional to the energyof the x-ray photon absorbed by the crystal of the detector. A gas-filled, proportional counterdetector is an ionization chamber filled with a mixture of noble and other gases. An x-rayphoton entering the chamber ionizes the gas atoms. The electric charge produced is collectedand provides an electric signal that is directly proportional to the energy of the x-ray photonabsorbed by the gas in the detector.

6.1.4 Data Processing Units: The key component in the data processing unit of anFPXRF instrument is the MCA. The MCA receives pulses from the detector and sorts themby their amptitudes (energy level). The MCA counts pulses per second to determine the heightof the peak in a spectrum, which is indicative of the target analyte's concentration. Thespectrum of element peaks are built on the MCA. The MCAs in FPXRF instruments have from256 to 2,048 channels. The concentrations of target analytes are usually shown in parts permillion on a liquid crystal display (LCD) in the instrument. FPXRF instruments can store bothspectra and from 100 to 500 sets of numerical analytical results. Most FPXRF instruments aremenu-driven from software built into the units or from PCs. Once the data–storage memoryof an FPXRF unit is full, data can be downloaded by means of an RS-232 port and cable to aPC.

6.2 Spare battery chargers.

6.3 Polyethylene sample cups: 31 millimeters (mm) to 40 mm in diameter with collar, orequivalent (appropriate for FPXRF instrument).

6.4 X-ray window film: Mylar , Kapton , Spectrolene , polypropylene, or equivalent; 2.5TM TM TM

to 6.0 micrometers (µm) thick.


6.5 Mortar and pestle: glass, agate, or aluminum oxide; for grinding soil and sedimentsamples.

6.6 Containers: glass or plastic to store samples.

6.7 Sieves: 60-mesh (0.25 mm), stainless-steel, Nylon, or equivalent for preparing soil andsediment samples.

6.8 Trowels: for smoothing soil surfaces and collecting soil samples.

6.9 Plastic bags: used for collection and homogenization of soil samples.

6.10 Drying oven: standard convection or toaster oven, for soil and sediment samples thatrequire drying.

7.0 REAGENTS AND STANDARDS

7.1 Pure Element Standards: Each pure, single-element standard is intended to producestrong characteristic x-ray peaks of the element of interest only. Other elements present must notcontribute to the fluorescence spectrum. A set of pure element standards for commonly soughtanalytes is supplied by the instrument manufacturer, if required for the instrument; not all instrumentsrequire the pure element standards. The standards are used to set the region of interest (ROI) foreach element. They also can be used as energy calibration and resolution check samples.

7.2 Site-specific Calibration Standards: Instruments that employ fundamental parameters(FP) or similar mathematical models in minimizing matrix effects may not require SSCS. If the FPcalibration model is to be optimized or if empirical calibration is necessary, then SSCSs must becollected, prepared, and analyzed.

7.2.1 The SSCS must be representative of the matrix to be analyzed by FPXRF.These samples must be well homogenized. A minimum of ten samples spanning theconcentration ranges of the analytes of interest and of the interfering elements must beobtained from the site. A sample size of 4 to 8 ounces is recommended, and standard glasssampling jars should be used.

7.2.2 Each sample should be oven-dried for 2 to 4 hours at a temperature of lessthan 150EC. If mercury is to be analyzed, a separate sample portion must remain undried, asheating may volatilize the mercury. When the sample is dry, all large, organic debris andnonrepresentative material, such as twigs, leaves, roots, insects, asphalt, and rock should beremoved. The sample should be ground with a mortar and pestle and passed through a 60-mesh sieve. Only the coarse rock fraction should remain on the screen.

7.2.3 The sample should be homogenized by using a riffle splitter or by placing 150to 200 grams of the dried, sieved sample on a piece of kraft or butcher paper about 1.5 by 1.5feet in size. Each corner of the paper should be lifted alternately, rolling the soil over on itselfand toward the opposite corner. The soil should be rolled on itself 20 times. Approximately5 grams of the sample should then be removed and placed in a sample cup for FPXRFanalysis. The rest of the prepared sample should be sent off site for ICP or AA analysis. Themethod use for confirmatory analysis should meet the data quality objectives of the project.

7.3 Blank Samples: The blank samples should be from a "clean" quartz or silicon dioxidematrix that is free of any analytes at concentrations above the method detection limits. These


samples are used to monitor for cross-contamination and laboratory-induced contaminants orinterferences.

7.4 Standard Reference Materials: Standard reference materials (SRM) are standardscontaining certified amounts of metals in soil or sediment. These standards are used for accuracyand performance checks of FPXRF analyses. SRMs can be obtained from the National Institute ofStandards and Technology (NIST), the U.S. Geological Survey (USGS), the Canadian NationalResearch Council, and the national bureau of standards in foreign nations. Pertinent NIST SRMsfor FPXRF analysis include 2704, Buffalo River Sediment; 2709, San Joaquin Soil; and 2710 and2711, Montana Soil. These SRMs contain soil or sediment from actual sites that has been analyzedusing independent inorganic analytical methods by many different laboratories.

8.0 SAMPLE COLLECTION, PRESERVATION, AND STORAGE

Sample handling and preservation procedures used in FPXRF analyses should follow the guidelinesin Chapter Three, Inorganic Analytes.

9.0 QUALITY CONTROL

9.1 Refer to Chapter One for additional guidance on quality assurance protocols. All fielddata sheets and quality control data should be maintained for reference or inspection.

9.2 Energy Calibration Check: To determine whether an FPXRF instrument is operatingwithin resolution and stability tolerances, an energy calibration check should be run. The energycalibration check determines whether the characteristic x-ray lines are shifting, which would indicatedrift within the instrument. As discussed in Section 4.10, this check also serves as a gain check inthe event that ambient temperatures are fluctuating greatly (> 10 to 20EF).

The energy calibration check should be run at a frequency consistent with manufacturersrecommendations. Generally, this would be at the beginning of each working day, after the batteriesare changed or the instrument is shut off, at the end of each working day, and at any other timewhen the instrument operator believes that drift is occurring during analysis. A pure element suchas iron, manganese, copper, or lead is often used for the energy calibration check. A manufacturer-recommended count time per source should be used for the check.

9.2.1 The instrument manufacturer’s manual specifies the channel or kiloelectronvolt level at which a pure element peak should appear and the expected intensity of the peak.The intensity and channel number of the pure element as measured using the radioactivesource should be checked and compared to the manufacturer's recommendation. If the energycalibration check does not meet the manufacturer's criteria, then the pure element sampleshould be repositioned and reanalyzed. If the criteria are still not met, then an energycalibration should be performed as described in the manufacturer's manual. With someFPXRF instruments, once a spectrum is acquired from the energy calibration check, the peakcan be optimized and realigned to the manufacturer's specifications using their software.

9.3 Blank Samples: Two types of blank samples should be analyzed for FPXRF analysis:instrument blanks and method blanks. An instrument blank is used to verify that no contaminationexists in the spectrometer or on the probe window.

9.3.1 The instrument blank can be silicon dioxide, a Teflon block, a quartz block,"clean" sand, or lithium carbonate. This instrument blank should be analyzed on each workingday before and after analyses are conducted and once per every twenty samples. An


instrument blank should also be analyzed whenever contamination is suspected by the analyst.The frequency of analysis will vary with the data quality objectives of the project. Amanufacturer-recommended count time per source should be used for the blank analysis. Noelement concentrations above the method detection limits should be found in the instrumentblank. If concentrations exceed these limits, then the probe window and the check sampleshould be checked for contamination. If contamination is not a problem, then the instrumentmust be "zeroed" by following the manufacturer's instructions.

9.3.2 A method blank is used to monitor for laboratory-induced contaminants orinterferences. The method blank can be "clean" silica sand or lithium carbonate thatundergoes the same preparation procedure as the samples. A method blank must be analyzedat least daily. The frequency of analysis will depend on the data quality objectives of theproject. To be acceptable, a method blank must not contain any analyte at a concentrationabove its method detection limit. If an analyte’s concentration exceeds its method detectionlimit, the cause of the problem must be identified, and all samples analyzed with the methodblank must be reanalyzed.

9.4 Calibration Verification Checks: A calibration verification check sample is used to checkthe accuracy of the instrument and to assess the stability and consistency of the analysis for theanalytes of interest. A check sample should be analyzed at the beginning of each working day,during active sample analyses, and at the end of each working day. The frequency of calibrationchecks during active analysis will depend on the data quality objectives of the project. The checksample should be a well characterized soil sample from the site that is representative of site samplesin terms of particle size and degree of homogeneity and that contains contaminants atconcentrations near the action levels. If a site-specific sample is not available, then an NIST or otherSRM that contains the analytes of interest can be used to verify the accuracy of the instrument. Themeasured value for each target analyte should be within ±20 percent (%D) of the true value for thecalibration verification check to be acceptable. If a measured value falls outside this range, then thecheck sample should be reanalyzed. If the value continues to fall outside the acceptance range, theinstrument should be recalibrated, and the batch of samples analyzed before the unacceptablecalibration verification check must be reanalyzed.

9.5 Precision Measurements: The precision of the method is monitored by analyzing asample with low, moderate, or high concentrations of target analytes. The frequency of precisionmeasurements will depend on the data quality objectives for the data. A minimum of one precisionsample should be run per day. Each precision sample should be analyzed 7 times in replicate. Itis recommended that precision measurements be obtained for samples with varying concentrationranges to assess the effect of concentration on method precision. Determining method precisionfor analytes at concentrations near the site action levels can be extremely important if the FPXRFresults are to be used in an enforcement action; therefore, selection of at least one sample withtarget analyte concentrations at or near the site action levels or levels of concern is recommended.A precision sample is analyzed by the instrument for the same field analysis time as used for otherproject samples. The relative standard deviation (RSD) of the sample mean is used to assessmethod precision. For FPXRF data to be considered adequately precise, the RSD should not begreater than 20 percent with the exception of chromium. RSD values for chromium should not begreater than 30 percent.

The equation for calculating RSD is as follows:

RSD = (SD/Mean Concentration) x 100


where:

RSD = Relative standard deviation for the precision measurement for theanalyte

SD = Standard deviation of the concentration for the analyteMean Concentration = Mean concentrati

Port Site Characterization Sampling and Analysis Plan ... · to monitor lead, zinc, and...

Documents

Transcript of Port Site Characterization Sampling and Analysis Plan ... · to monitor lead, zinc, and...